1. Field of the Invention
The present invention relates to a technique effectively applied to a deck locking mechanism capable of accommodating decks in tiers.
2. Description of the Related Art
In a deck tower accommodating magnetic tape drive units etc. in tiers known is a mechanism formed of a rigid metal frame assembled into shelves in tiers, including a wheel mounted to the bottom thereof for the easy movement, a deck tray at each shelf so as to be drawn toward the back of the deck tower, and a deck (drive unit) fixed onto the deck tray. In other words, for a maintenance on the decks mounted in the deck tower, the deck trays must be drawn to the back of the deck tower.
When heavy decks such as magnetic tape drive unit are employed, if two or more deck trays are drawn from the same deck tower, the center of gravity of the deck tower will fall outside on the back side, causing a risk of collapsing the deck tower itself, potentially leading to serious accidents.
In order to avoid this, the deck tower may be fixed to the floor; however, it would be inconveniently difficult to move the deck tower.
Therefore, the only option to prevent the deck tower from collapsing with a movable deck tower structure is that a maintenance operator""s care must be thoroughly taken not to draw two or more deck trays from the same deck tower at the same time.
The present invention has been made in view of the above-stated problems, and its technical object is to structurally prevent an operator from recklessly drawing a plurality of deck trays.
In order to solve the foregoing problems, the present invention adopts the following procedure.
A deck shelf at an upper tier and a deck shelf at a lower tier respectively include stopper mechanisms for preventing decks from being drawn so that these stopper mechanisms at the upper and lower shelves may be linked with each other. The xe2x80x9clinkxe2x80x9d as used herein means a mechanism such that one operation is permitted while the other operation is prevented, or it means that one operation and the other operation are cooperated with each other.
More specifically, the present invention provide a deck apparatus in a deck tower having deck shelves in tiers, the deck tower from which decks accommodated in the deck shelves are drawable, the deck apparatus comprising: a stopper member movably provided at each deck shelf for preventing the decks from being drawn; and a locking arm for, when the stopper member at any shelf is moved to release the prevention of drawing the decks, preventing the stopper members at the remaining shelves from moving. The locking arm only permits a deck to be alternatively drawn to prevent the deck tower from collapsing.
Instead of the locking arm, cams, which operated with the sliding movement of the stopper members to rotate, may be provided, and a link arm may be provided between the cams at the upper and lower deck shelves. These cams are interlocked with each other so that when the link arm urges either stopper member at the upper or lower tier to move in the direction permitting the deck to be drawn, the other stopper member may be positioned to prevent the decks from being drawn. This may only permit a deck to be alternatively drawn to prevent the deck tower from collapsing.